Combine cream cheese, sugar substitute, and vanilla extract in a bowl and mix
well. Beat the heavy cream in a separate bowl until it forms soft peaks. Fold
the whipped cream into the cream cheese mixture.

Transfer the mixture to a large glass bowl and chill, covered with plastic
wrap, for at least 25 minutes. Top with berries if you like. Serve immediately
or store, covered with plastic wrap, in the refrigerator for up to 2 days.